How difficult is it to astromodify a canon DSLR?

[malc-c]

An edited text from Gary's website - I've underlined the key parts -

450D: In April 2008, I completed a modification of the Canon Digital Rebel XSi (450D) to remove its IR Cut filter. Removal of the filter allows for a great increase in sensitivity to the color red and the H-Alpha wavelength important for deep sky imaging. Instead of installing a clear optical glass to replace the original Canon IR Cut filter as I had done for the 300D modification, I installed a Baader "DSLR Correcting Filter" which is a much milder UV-IR-Cut filter that allows the H-Alpha wavelength to pass for deep sky, but blocks higher infrared wavelengths that cause poor focus and bloated stars with refractor telescopes and camera lenses. This filter still allows the 450D to be used with an infrared pass filter, such as the HOYA R72, to take daytime infrared images with focusing via the live-view feature.  Another option is to install a clear glass of equal thickness (0.57mm) of the IR filter to maintain viewfinder focus accuracy and the camera's autofocus. Lifepixel.com sells such a clear optical glass. A third option is to just remove the original Canon IR Cut filter and replace it with nothing, but the autofocus will not work. Since the 450D has the live view focusing feature, using it instead would work well for astro imaging (and daytime images) even if the original IR Cut filter was removed and replaced with nothing.

[AlanP_]

15 minutes ago, malc-c said:

An edited text from Gary's website - I've underlined the key parts -

450D: In April 2008, I completed a modification of the Canon Digital Rebel XSi (450D) to remove its IR Cut filter. Removal of the filter allows for a great increase in sensitivity to the color red and the H-Alpha wavelength important for deep sky imaging. Instead of installing a clear optical glass to replace the original Canon IR Cut filter as I had done for the 300D modification, I installed a Baader "DSLR Correcting Filter" which is a much milder UV-IR-Cut filter that allows the H-Alpha wavelength to pass for deep sky, but blocks higher infrared wavelengths that cause poor focus and bloated stars with refractor telescopes and camera lenses. This filter still allows the 450D to be used with an infrared pass filter, such as the HOYA R72, to take daytime infrared images with focusing via the live-view feature.  Another option is to install a clear glass of equal thickness (0.57mm) of the IR filter to maintain viewfinder focus accuracy and the camera's autofocus. Lifepixel.com sells such a clear optical glass. A third option is to just remove the original Canon IR Cut filter and replace it with nothing, but the autofocus will not work. Since the 450D has the live view focusing feature, using it instead would work well for astro imaging (and daytime images) even if the original IR Cut filter was removed and replaced with nothing.

Brilliant! So I can get away without using the clear glass at all as I wont be using it for general photography. Thanks a million for clearing that up, i've been all day trying to find a definite answer!

[Stuf1978]

1 hour ago, AlanP_ said:

Is that with the filter removed and no clear glass installed? I read that if you dont replace it with the clear glass or use a clip in IV/IR filter you get bloated stars.

Yeah filter removed and no clear glass installed. Can't say I've ever noticed bloated stars (still pretty new to astrophotography). Here's an image taken with my self modded 450d with the L-eNhance clip in filter

 

 

[AlanP_]

6 minutes ago, Stuf1978 said:

Yeah filter removed and no clear glass installed. Can't say I've ever noticed bloated stars (still pretty new to astrophotography). Here's an image taken with my self modded 450d with the L-eNhance clip in filter

 

 

Thats great so! Thats a fantastic shot too. I was thinking of getting the L-eXtreme. What gear was that taken with and how long?

[Stuf1978]

2 minutes ago, AlanP_ said:

Thats great so! Thats a fantastic shot too. I was thinking of getting the L-eXtreme. What gear was that taken with and how long?

Thanks, It was 37 x 7 minute subs (total of 4.5 hours ish) with the 450D, Skywatcher ED72 on a HEQ5 pro from a bortle 8 sky. I'm looking to upgrade to a dedicated cooled camera later this year and was also thinking of pairing it with an L-eXtreme 👍

[AlanP_]

14 minutes ago, Stuf1978 said:

Thanks, It was 37 x 7 minute subs (total of 4.5 hours ish) with the 450D, Skywatcher ED72 on a HEQ5 pro from a bortle 8 sky. I'm looking to upgrade to a dedicated cooled camera later this year and was also thinking of pairing it with an L-eXtreme 👍

Fingers crossed I successfully modify it now!

[malc-c]

On 02/01/2021 at 22:58, Stuf1978 said:

Yeah filter removed and no clear glass installed. Can't say I've ever noticed bloated stars (still pretty new to astrophotography). Here's an image taken with my self modded 450d with the L-eNhance clip in filter

 

That's a contradiction of terms.  Alan was asking about removing both IR filters and using the camera in that basis... you are using a clip filter (and a very expensive one at that) to do the same job as the Badder modification which replaces the canon IR cut filter

Quote

Optolong believes the design of our L-eNhance filter is a technical innovation among filters. It effectively isolates the H-Alpha, H-Beta, and Oxygen III nebula emission lines and achieves a maximum transmission of up to 90%.

As you have a filter in the optical path it's quite possible that this is the reason the stars are not bloated.

Very nice image by the way 😉

 

 

[Stuf1978]

1 minute ago, malc-c said:

That's a contradiction of terms.  Alan was asking about removing both IR filters and using the camera in that basis... you are using a clip filter (and a very expensive one at that) to do the same job as the Badder modification which replaces the canon IR cut filter

As you have a filter in the optical path it's quite possible that this is the reason the stars are not bloated.

Very nice image by the way 😉

 

 

Thank you

I stand corrected, I never knew this. I don't think I've ever used the camera without some form of filter since modification so that's probably why I've never noticed enlarged stars. I do have plans to shoot some targets with a combination of filtered and unfiltered subs if the weather ever plays ball so I'll see what results I get.

[Rustang]

On 04/01/2021 at 10:25, malc-c said:

That's a contradiction of terms.  Alan was asking about removing both IR filters and using the camera in that basis... you are using a clip filter (and a very expensive one at that) to do the same job as the Badder modification which replaces the canon IR cut filter

As you have a filter in the optical path it's quite possible that this is the reason the stars are not bloated.

Very nice image by the way 😉

 

 

Ive just come across your reply as I'm looking into my filters etc/ I have a Baader modified 600D, I also have an Optolong L enhance filter that Ive been using, and from what I under stand from what you said is that the Baader mod is doing the same thing as placing an L enhance filter over a non Baader modified camera so technically I don't really need my L enhance filter then? I'm pretty sure its making some difference though, but never done any comparisons with and without.

[malc-c]

You would need to check the light emission graphs, but basically yes.   

Baader Filter

 

The Optolong filter is more tuned to allow light around the 500nm and 660nm and cut out everything before, after and in between...where as the Baader passes everything between 400 and 700nm  but then allowed longwave IR around the 1100nm to pass.  

I may be wrong, but IMO in effect they are doing the same thing, just one is more tuned than the other.  You might not have needed to have had the Baader filter mod done giver that the Optolong is tuned to pass Hb, OIII and Ha wavelengths which are the key wavelengths..  It makes no odds really, its the end result that matters and that's a cracking image - If you're happy with the results then no need to change things

[SpaceDave]

On 02/01/2021 at 23:37, AlanP_ said:

Fingers crossed I successfully modify it now!

Hello Alan. I'm in the same boat. Did you get around to removing the filter and how were the results? Thanks.

[SpaceDave]

On 02/01/2021 at 22:58, Stuf1978 said:

Yeah filter removed and no clear glass installed. Can't say I've ever noticed bloated stars (still pretty new to astrophotography). Here's an image taken with my self modded 450d with the L-eNhance clip in filter

 

 

Fantastic image.

[Iceman120]

I'm thinking of modifying my 550d, rather than buying a ir pass replacement could i replace the low pass filter with a CLS filter? 

thanks guys